Welcome to Ben Greenfield's Weekly Roundup!
In this weekly post, I share with you my most interesting discoveries of the week, including the latest news on the fronts of fitness, nutrition, health, wellness, biohacking, and anti-aging research. I also recap my upcoming events and special announcements so you can keep up with opportunities to learn, giveaways, discounts, and more!
New Discoveries
Still Doing 45-Minute Cardio Sessions? *This* 9-Minute Cycling Method Cuts Your Workout Time Down by 80% (Without Decreasing Important Health Benefits!) 🚴♂️
I’m obsessed with efficiency, so when I’ve got a 15-minute gap between a podcast recording and a consult call, I’m not wasting it doomscrolling on my phone.
Instead, I like to fit in an efficient (yet powerful) workout on my CAROL Bike—which taps into a potent form of exercise science: reduced exertion high-intensity interval training (REHIT).
My CAROL Bike delivers an 8–9 minute protocol that packs similar cardiorespiratory and mitochondrial benefits as a traditional 45-minute moderate-intensity session.
Yes… 45 minutes condensed into nine.
The AI-driven resistance calibrates to your exact physiology, adjusting in real time to generate authentically maximal sprints. It's not “kinda hard,” but the precise wattage needed to trigger:
- Mitochondrial biogenesis
- Activation of adenosine monophosphate–activated protein kinase (AMPK), a cellular energy-sensing enzyme that improves the body’s ability to switch between using carbohydrates and fats for fuel
- VO₂ max improvements
- A massive post-exercise oxygen consumption (EPOC) wave that keeps your metabolism elevated long after the session ends
Two 20-second all-out sprints, some strategic recovery, and boom: my nervous system is lit up, my insulin sensitivity is tuned, and I’m primed for the rest of the day.
Then I’ll step off my bike, sometimes hit a cold shower, and walk into my next meeting feeling clear-headed, energized, and fully switched on.
Right now, CAROL is offering its biggest discount of the year: $300 off with code BEN.
If you want the most scientifically efficient cardio tool on the market—delivering comparable benefits in 80% less time—you can grab yours here.
Want to go deeper on the CAROL Bike and mastering true HIIT from home? You can start by exploring these resources:
- How To Get the Benefits Of A 45-Minute Run In Under 9 Minutes (& A 12% VO2 Max Increase & 62% Lower Risk Of Diabetes): The New AI Bike That Is Taking The Fitness World By Storm.
- The Truth About Zone 2 Cardio, Mitochondrial Health & How REHIT Beats It (In Less Time!) With Ulrich Dempfle.
- How to Banish Frustrating Fitness “Plateaus” with Science-Backed MINIMUM Effective Dose Exercise (+ the *Ultimate* Blueprint for a Boundless Body).
- 4 Reasons To DO HIIT, How To Get Muscular Legs, How To Test For Gut Inflammation, Natural Ways To Increase Stem Cells, and Should You Use Ice Baths & Antioxidants After A Workout?
- The Minimum Effective Dose Of Exercise, How Ben Greenfield Fasts, Increasing Mitochondrial Density & Much More!
*This* Simple Upgrade Turns a Boundless Bar Into Something You’d Expect Behind a Bakery Counter
If you haven’t tried the world’s first ketone-powered protein bar yet, now is the perfect time to experience ketone-fueled energy (without the bitter ketone taste or the strict keto diet).
Here’s a simple, dairy-free, mouth-watering keto frosting that pairs *perfectly* with the sticky goodness of the Boundless Bar Cinnamon Roll flavor.
Keto Frosting Recipe (Dairy-Free):
In a mixing bowl, whisk together:
- 1 can of coconut cream
- 4 dropperfuls of vanilla stevia (Omica Organic is a clean, great-tasting option)
- ½ tsp vanilla extract
- A pinch of salt
Spread generously over your Boundless Bar.
Eat. Moan. Repeat.
You can grab your bars here at BoundlessBar.com—and bonus points if you drop a comment with your own Boundless Bar recipe idea!
*Here’s* How to Receive Coaching, Workouts & Biohacking Support—with TRIUMPH Coaching
I get it—navigating your health and fitness in today’s world can feel like chasing a moving target. One week, it’s about your macros, the next, it’s wearables and peptide stacks.
When was the last time you had an actual team helping you sort through the noise, guiding you step by step based on your unique biomarkers, goals, and lifestyle?
With TRIUMPH Coaching, you gain access to elite-level support without the guesswork.
We have different coaching plans to meet you wherever you are. Work 1-on-1 with one of my expert coaches, or as part of a group.
Whatever you choose, you’ll be rooted in real-time adjustments and results. If your goals involve optimizing VO2 max, chasing longevity, or just trying to build muscle and mobility right from your living room, we’ve got you covered.
Want to explore your TRIUMPH coaching options?
Fill out our coaching form, and one of our expert coaches will reach out to discuss how to help you achieve extraordinary fitness and peak performance.
My 2025 Holiday Gift Guide Is Here! 25 *Handpicked* Wellness Gifts for Stronger Bodies, Sharper Minds & Joy All Year Long
The holidays are a reminder of what really matters—connection, meaning, and the people you hold close.
And while most gifts fade, the ones that enhance and support health keep giving, because when you give something that nurtures well-being, you’re providing energy, clarity, and a better way to live day after day.
After testing and studying the most effective tools for vitality and longevity, I’ve *handpicked* 25 gifts for you.
You’ll find them all in my 2025 Holiday Gift Guide—each one chosen to help you and the people you love feel your best, this season and beyond.
This Week in Health & Performance: What the Latest Research Says
🔥 The Muscle-Gain Sweet Spot: A small calorie surplus—between 150–300 kcal/day (5–10% of total), ideally from protein—maximizes muscle gain while minimizing fat. Surpluses above 15% lead to significantly more FAT gain, so don't go overboard (study here, and another study).
⏱️ Fasting vs. Calorie Restriction: New evidence shows fasting can help with structure and appetite control, but for long-term weight loss, calorie restriction still wins. Fasting isn’t superior overall, but it can still make adherence easier (read the study here).
❄️ Humans Adapt FAST: Like Japanese Ama divers, humans—especially kids—adapt quickly to environmental stressors like cold exposure, breathwork, and load-bearing movement. Translation: train adaptability early to make your kids more resilient (full study here).
🧴 Microplastic Panic? Maybe Overblown: While plastic consumption still poses health risks, total human exposure—especially the dramatic “credit card a week” claims—may be far lower than popular narratives suggest (analysis here).
Key Takeaway: Muscle gain, metabolic health, and environmental resilience all come down to small, strategic habits, so dial in your calories, structure your fasting intelligently, and train your body to adapt.
Want to dive deeper? Click the links above to explore the research, and click here to follow me on X for all the latest health and performance news hot off the press!
Product Of The Week
::: Save 15% on ZBiotics Pre-Alcohol: My Go-To Holiday Hack 🍷🧬 :::
If you’re anything like me, the holiday season brings a few extra clinks of the glass.
And that leads to the familiar dilemma: do you enjoy the celebration tonight… or pay for it in tomorrow’s performance?
For the past few years, I’ve relied on one of my favorite holiday biohacks to help me do both: ZBiotics Pre-Alcohol.
This genetically engineered probiotic is designed to break down acetaldehyde, the toxic byproduct of alcohol that contributes to feeling “off” the next day.
I’ve used ZBiotics Pre-Alcohol through multiple holiday seasons, travel stretches, and social events, and the difference is absolutely noticeable.
Drink one before your first cocktail, and you’re essentially giving your body a molecular head start. You'll wake up ready for your workout, family time, travel day, or whatever December throws your way—even after having fun the night prior.
As you head into celebration season, don’t just toast; biohack your night and protect your next morning.
Try ZBiotics Pre-Alcohol and experience the shift for yourself. Right now, you can use code BENG here, and you'll save 15% on your first order.
P.S.: ZBiotics offers a 100% money-back guarantee. So if you don’t feel the difference, they refund you—no questions asked.
Podcasts I Recorded This Week:
The Latest Content I Was Featured On This Week:
My Article Feed:
My full article feed and all archives of my articles are here.
Upcoming Events:
CREATE 26 — January 28–30, 2026
Join me in Tucker, Georgia, at CREATE 26, a high-level gathering of founders, creators, and leaders focused on building scalable businesses, powerful networks, and aligned lives. This immersive multi-day experience blends strategy, leadership, and personal optimization with real-world execution and high-impact connections. You’ll also have the opportunity to join me for select sessions and a special Health Panel Q&A on Thursday, January 29. If you’re serious about growth in both business and life, this is a room you want to be in. Grab your ticket here.
Stay tuned for future updates—and you can always keep up with my LIVE appearances by checking out bengreenfieldlife.com/calendar!
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Cheers,
Ben
One Response
How do you decide which emerging fitness or biohacking tools are worth integrating long term versus using as short-term experiments, especially when efficiency gains look impressive but real-world sustainability and adherence matter just as much?